Environmental effects on productive and reproductive performance of Pelibuey ewes in Southeastern M????xico

摘要

ABSTRACT The objective of this study was to determine the effect of some environmental factors on reproductive and productive performance traits and to estimate their repeatability in Pelibuey ewes in Yucatan, Mexico. Information of 956 Pelibuey ewes lambing from 2007 to 2013 in three farms were used ( n ?￠????=?￠????2215 lambing). The assessed traits were age at first lambing (AFL), lambing interval (LI), litter size at birth (LSB), litter size at weaning (LSW), litter weight at birth (LWB) and litter weight at weaning adjusted to 60 days (LWWA). Mixed models were used to determine the effects of farm, lambing season or birth, year of lambing or birth and parity number on above traits. Repeatability were calculated using the between and within ewe components of variance. Overall means and standard deviations for AFL, LI, LSB, LWB, LSW and LWWA were 526.7?￠???????±?￠????107.1d, 259.4?￠???????±?￠????70.3d, 1.5?￠???????±?￠????0.6, 4.3?￠???????±?￠????1.6?￠????kg, 1.4?￠???????±?￠????0.7 and 19.1?￠???????±?￠????10.1?￠????kg, respectively. Repeatability for LI, LSB, LSW, LWB and LWWA were 0.06?￠???????±?￠????0.20, 0.12?￠???????±?￠????0.04, 0.00?￠???????±?￠????0.04, 0.13?￠???????±?￠????0.04 and 0.01?￠???????±?￠????0.04, respectively. AFL was not affected by any of the environmental factors. However, the other traits were influenced ( p ?￠????